Q: A question came up the other day in a driving class I was teaching regarding seatbelt extenders. One student said he had been told by a state trooper that they were not legal. You being the guru of traffic, can you clarify this for us?

A: First, I prefer to be called a Level 4 Jedi Master of Transportation. But I'll accept the title of traffic guru. (This time.) Second, you have to delve pretty deep into the abyss of Oregon statutes to find an answer – and it's not exactly clear.

For the puzzled, seatbelt extenders have become popular with plus-size drivers who feel squeezed with the automakers' established belt specs (a seated hip circumference of 47.2 inches and a waist circumference of 42.5 inches).

On one end, a metal tongue clicks into the a seat's built-in buckle. On the other, a new buckle to make the connection with the belt.

It's easy to find these things. On eBay, they're more ubiquitous than liquidated Charlie Sheen "Winning" T-shirts. But be cautious. (This is where the traffic-jedi training kicks in.)

When protecting life and limb at 55 mph, avoid buying after-market safety accessories online. With seatbelt extenders, go to a dealership specializing in your make of vehicle, where they're usually gratis. "We give them away regularly," said Shintaro Andrew, a parts manager at Tigard's Landmark Ford.

If the local dealer can't help, go to an auto-parts store. Compliant systems will be labeled "FMVSS 209."

Q: If I'm already on the far right, biking in the bike lane up North Williams Avenue in Portland, need I further yield to Legacy Emanuel Medical Center ambulances by stopping?

A: Bicycle rights, man. You want to be treated equally on the road? The law says you are indeed equal to a motorist when calamity needs you to get the heck out of the way. ORS 811.145 requires a "person" operating a "vehicle" (and a bicycle is defined as a vehicle by statute) to yield the right of way to an emergency vehicle with a visual or audible signal. You need to stop as near as possible to the right curb or edge of the road and and remain there until the emergency vehicle passes.

The law "also requires that pedestrians yield the right of way to emergency vehicles," said Portland attorney Ray Thomas, who specializes in bicycling and pedestrian issues.

Even if the law gave bicyclists a pass, ask yourself: Are a few seconds of inconvenience for you really worth getting in the way of that ambulance and the person who needs its help?

View full sizeJohn Killen/The OregonianWant one of these? No, not the rainstorm or the umbrella; the shelter. You may need to recruit some friends to ride Tri-Met with you. See the question and answer below.

Q: I've noticed several spanking new TriMet bus shelters, including one a few stops away from mine on Southwest 72nd in Tigard. As winter approaches, I'd love to have shelter and bench at my Line 38 stop. How would I go about getting one?

A: TriMet only considers placing shelters at stops with 50 or more daily boardings. "Once that threshold is met," said TriMet spokeswoman Roberta Altstadt, "a planner evaluates the public right-of-way to determine if there is sufficient space to safely place a shelter." There has to also be adequate room for pedestrians and bus boardings, Altstadt said.

Most of the new shelters you're seeing, including the one on 72nd, actually replaced old, worn-out ones.

Maybe you can persuade more of your neighbors to take TriMet to work. Of course, considering the dubious state of bus service in the suburbs these days, you'll need some mad pitching skills. Until then, invest in a sturdy umbrella.